스프링 서버에서 이미지를 encodeBase64String으로 string으로 변환해준 다음 JSON으로 key value값으로 안드로이드로 넘겨줍니다. 그런데 안드로이드에서 이미지에서만 자꾸 오류가 뜨네요 코드입니다.

MainActivity.java

class BackgroundTask extends AsyncTask { String target;

    @Override
    protected void onPreExecute()
    {
        target="아이피";
    }

    @Override
    protected String doInBackground(Void... voids)
    {
        try
        {
            URL url=new URL(target);
            HttpURLConnection httpURLConnection=(HttpURLConnection)url.openConnection();
            InputStream inputStream=httpURLConnection.getInputStream();
            BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(inputStream,"utf-8"));
            String temp;
            StringBuilder stringBuilder=new StringBuilder();
            while((temp=bufferedReader.readLine())!=null)
            {
                stringBuilder.append(temp+"\n");
            }
            bufferedReader.close();
            inputStream.close();
            httpURLConnection.disconnect();

            Log.d("message",stringBuilder.toString().trim());
            return stringBuilder.toString().trim();

        }catch (Exception e)
        {
            e.printStackTrace();
        }
        return null;

    }

    @Override
    public void onProgressUpdate(Void... values)
    {
        super.onProgressUpdate(values);
    }

    public void onPostExecute(String result)
    {
        try{
            JSONObject jsonObject=new JSONObject(result);
            JSONArray jsonArray=jsonObject.getJSONArray("response");
            int count=0;
            String postUserid,postTitle,postContents,postDate;


            while(count<jsonArray.length()){
                JSONObject object=jsonArray.getJSONObject(count);
                postUserid=object.getString("creatorId");
                postTitle=object.getString("title");
                postContents=object.getString("contents");
                postDate=object.getString("image");
                adapter.addItem(new Person(postUserid,postTitle,postContents,postDate));
                count++;

            }

        }catch (Exception e){

        }
    }


}

위에서 image값으로 String으로 받아줍니다. 그리고 Person객체파라미터로 집어 넣고

Person.java

public class Person {

String userId; String title; String contents; String image;

public Person(String userId, String title, String contents, String image) {
    this.userId = userId;
    this.title = title;
    this.contents = contents;
    this.image=image;
}

public String getUserId() {
    return userId;
}

public void setUserId(String userId) {
    this.userId = userId;
}

public String getTitle() {
    return title;
}

public void setTitle(String title) {
    this.title = title;
}

public String getContents() {
    return contents;
}

public void setContents(String contents) {
    this.contents = contents;
}


public String getImage() {
    return image;
}

public void setImage(String image) {
    this.image = image;
}

}

adapter에 넣어줘 메인화면에 띄워줄려고 합니다. adapter부분에서 String image를 디코딩 하는 부분입니다.

PersonAdapter.java 의 setItem부분(BindViewHolder)

public void setItem(Person item){ String data=item.getImage(); Log.d("image",item.getImage()); byte[] byteArray= Base64.decode(data,0);

        ByteArrayInputStream inputStream=new ByteArrayInputStream(byteArray);

        Bitmap bitmap= BitmapFactory.decodeStream(inputStream);
        uploadImage.setImageBitmap(bitmap); //에러나는부분
        userId.setText(item.getUserId());
        title.setText(item.getTitle());
        contents.setText(item.getContents());
    }

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.jungbo.j4android.mynewist, PID: 5549 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setImageBitmap(android.graphics.Bitmap)' on a null object reference at com.jungbo.j4android.mynewist.PersonAdapter$ViewHolder.setItem(PersonAdapter.java:112) at com.jungbo.j4android.mynewist.PersonAdapter.onBindViewHolder(PersonAdapter.java:40) at com.jungbo.j4android.mynewist.PersonAdapter.onBindViewHolder(PersonAdapter.java:22) at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6781) at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6823) at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5752) at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6019) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5854) at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2230) at android.support.v7.widget.GridLayoutManager.layoutChunk(GridLayoutManager.java:557) at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1517) at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:612) at android.support.v7.widget.GridLayoutManager.onLayoutChildren(GridLayoutManager.java:171) at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3924) at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3336) at android.view.View.measure(View.java:23169) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1535) at android.widget.LinearLayout.measureVertical(LinearLayout.java:825) at android.widget.LinearLayout.onMeasure(LinearLayout.java:704) at android.view.View.measure(View.java:23169) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at android.view.View.measure(View.java:23169) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749) at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:733) at android.support.design.widget.HeaderScrollingViewBehavior.onMeasureChild(HeaderScrollingViewBehavior.java:95) at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onMeasureChild(AppBarLayout.java:1556) at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:803) at android.view.View.measure(View.java:23169) at android.support.v4.widget.DrawerLayout.onMeasure(DrawerLayout.java:1119) at android.view.View.measure(View.java:23169) at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715) at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461) at android.view.View.measure(View.java:23169) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:143) at android.view.View.measure(View.java:23169) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1535) at android.widget.LinearLayout.measureVertical(LinearLayout.java:825) at android.widget.LinearLayout.onMeasure(LinearLayout.java:704) at android.view.View.measure(View.java:23169) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at android.view.View.measure(View.java:23169) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749) E/AndroidRuntime: at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1535) at android.widget.LinearLayout.measureVertical(LinearLayout.java:825) at android.widget.LinearLayout.onMeasure(LinearLayout.java:704) at android.view.View.measure(View.java:23169) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6749) at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) at com.android.internal.policy.DecorView.onMeasure(DecorView.java:716) at android.view.View.measure(View.java:23169) at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2718) at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1572) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1855) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1460) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7183) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:949) at android.view.Choreographer.doCallbacks(Choreographer.java:761) at android.view.Choreographer.doFrame(Choreographer.java:696) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:935) at android.os.Handler.handleCallback(Handler.java:873) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:6669) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)